In terms of diversity and women on lists and such, there's nothing in the electoral rules that formally requires it. It's really been left to the parties to deal with that and create a more inclusive, representative Parliament.
Parties have tried various devices to ensure a better representation amongst women. For instance, the Labour Party in the European elections requires the list to be female, male, female, male, alternating down the list.
In the past, in the Scottish Parliament election, again the Labour Party used a thing called “pairing”. It was in the early life of the Parliament when the Labour Party was winning a lot of the constituency seats. They paired two constituencies and they had to be winnable constituencies. Of the two, the party required one candidate to be a male and one candidate to be a female.
But all these things are really left to the parties to decide.